Number needed to treat (NNT) and number needed to harm (NNH) in RA clinical trials and systematic reviews. *95% CI not calculated for non-significant results. SSZ, sulfasalazine; MTX, methotrexate; CYC, cyclophosphamide; AZA, azathioprine; D-Pen, D-penicillamine; CsA, cyclosporin A; Pred, prednisolone; TJC, tender joint count.